1. Field of the Invention
The invention relates in general to escalators, and more specifically, to escalators having a demarcation strip adjacent to the lateral edge of each step.
2. Description of the Prior Art
U.S. Pat. No. 2,981,397 discloses several embodiments of escalators directed to reducing the possibility of objects entering and being caught between relatively moveable parts of an escalator. In one embodiment, the outer tread cleat located at each lateral edge of each step tread part is formed of a resilient material bendable in a direction which tends to close the step-skirt gap, should force be applied to it.
U.S. Pat. No. 3,986,595 discloses a two-element arrangement designed to narrow the step-skirt gap, including a sensor element actuated by a passenger which in turn operates a displacement element located to narrow the gap.
U.S. Pat. No. 4,236,623 discloses placing a plastic strip along each lateral edge of the step tread. The strips include ribs which extend into the grooves between the tread cleats, with the upper portion being dimensioned to narrow the running clearance between the steps and the skirts. The upper portion also includes an inclined ramp to guide objects away from the step-skirt interface.
U.S. Pat. No. 4,397,383 discloses placing a resilient strip along each lateral edge of a step tread, which has a rib for extending into the groove between the two outermost tread cleats. The upper portion is cantilevered towards the skirt and is designed to permit substantial flexure under the weight of a passenger's foot, and to also bend to permit release of an object should it become entrapped between the cantilevered portion of the strip and the skirt.
U.S. Pat. No. 4,413,791 closes the step-skirt gap entirely in one embodiment, by providing continuous sliding contact between the plastic bearing plates fixed to the sides of the steps, and the adjacent skirt. In another embodiment, resilient "curbs" have ribs which snap into the grooves between the tread cleats at the lateral edges of a step. An upper portion extends towards and makes continuous contact with the adjacent skirt.